Question 1

Find the odd group of letters from the following alternatives based on the regularity of the skip pattern in the alphabet.

Accepted Answer

Introduction / Context: This question tests your ability to identify consistent step patterns across multiple letters in a group. Recognizing evenly spaced sequences in the alphabet is a critical skill in verbal reasoning and series based questions. Given Data / Assumptions: The letter groups provided are: ACEG, KMNP, HJLN, and TVXZ. You need to select the group that does not follow the same regular skip pattern as the others. Assume that letters are mapped to positions A = 1, B = 2, up to Z = 26. Concept / Approach: The idea is to convert each letter group into a sequence of numerical positions and then examine the differences between consecutive positions. If three groups have a constant step size, such as +2, and one group does not, that irregular group becomes the odd one out. Step-by-Step Solution: Step 1: Consider ACEG. The letters A, C, E, and G have positions 1, 3, 5, and 7. The differences are +2, +2, and +2, so this group follows a regular +2 step pattern. Step 2: Consider HJLN. The letters H, J, L, and N have positions 8, 10, 12, and 14. The successive differences are again +2, +2, and +2, so this group also follows the same regular +2 pattern. Step 3: Consider TVXZ. The letters T, V, X, and Z have positions 20, 22, 24, and 26. The differences are +2, +2, and +2, so this group also maintains the same +2 skip pattern. Step 4: Now look at KMNP. The letters K, M, N, and P correspond to positions 11, 13, 14, and 16. The differences here are +2 from 11 to 13, +1 from 13 to 14, and +2 from 14 to 16, which is not a uniform step. Step 5: Since ACEG, HJLN, and TVXZ all follow a consistent +2 skip pattern, while KMNP does not, KMNP is the odd letter group. Verification / Alternative check: You can verify this further by visually writing out the alphabet and marking the letters involved. ACEG will highlight every second letter from A onward. HJLN and TVXZ show the same pattern of skipping one letter between each chosen letter. KMNP, however, shows an irregular pattern where the skip is not uniform between all letters. This visualization confirms the irregularity of KMNP compared to the others. Why Other Options Are Wrong: ACEG: Shows a perfect +2 pattern throughout, so it matches HJLN and TVXZ. HJLN: Also maintains a regular +2 increment between each adjacent letter, so it is not odd. TVXZ: Continues the same pattern near the end of the alphabet, so it clearly fits the main rule. Common Pitfalls: Some students may focus only on the idea that letters are spaced out and may not notice that in KMNP the spacing changes in the middle. A careful check of numeric positions and differences avoids such oversight. Always compute all intermediate gaps, especially when groups involve more than two letters. Final Answer: KMNP

Question 2

Find the odd pair from the following alternatives based on the type of relationship between the two words.

Accepted Answer

Introduction / Context: This question assesses your understanding of conceptual relationships between word pairs. It invites you to analyze how the first item in each pair is related to the second, and then identify which pair has a different kind of relationship from the others. Given Data / Assumptions: The pairs given are: Teacher and Student, Chemistry and Science, History and Mathematics, Air and Oxygen. You must choose the pair whose relationship does not match the pattern observed in the majority of pairs. Assume common educational and scientific meanings of the terms. Concept / Approach: The analysis relies on seeing whether one term is a subset or part of the other or whether the pair forms a special type of association. In two of the pairs, one item is a broader category and the other is a specific example or component of that category. In another pair, the two items are in a direct relational role. The odd pair is the one in which both items are equal level categories without a subset or role based relationship. Step-by-Step Solution: Step 1: Teacher and Student share a relational role. A teacher teaches, and a student learns. The relationship is that of a person who imparts knowledge and a person who receives it. Step 2: Chemistry and Science have a subset relationship. Science is the broad field, and chemistry is one of its branches. Thus, chemistry is a part of science. Step 3: Air and Oxygen also show a part whole relationship. Air is a mixture of gases, and oxygen is one of the major components of air. Step 4: History and Mathematics, however, are two separate academic subjects that are both branches of knowledge but not subsets of each other. One is not a specific type of the other, and they are not in a component relationship. Step 5: Therefore, History and Mathematics form a pair of co equal categories, unlike the other pairs, which show either component or role based relationships, making History and Mathematics the odd pair. Verification / Alternative check: You can reframe the relationships as a short sentence for each pair. A teacher teaches a student, chemistry is a branch of science, oxygen is a component of air. These can all be written as either X works with Y or X is part of Y. However, you cannot accurately say that history is part of mathematics or mathematics is part of history. Both subjects stand independently under the larger umbrella of education, so they do not match the other relationship patterns. Why Other Options Are Wrong: Teacher and Student: This is a clear role based relationship, where one directly interacts with and influences the other. Chemistry and Science: This is a subset relationship, where chemistry is a part of the broader domain of science. Air and Oxygen: This is a composition relationship, where oxygen is one of the components that make up air. Common Pitfalls: Some learners may focus only on whether the terms come from education or science and become confused by category differences. The key is to think about how the two words in each pair are connected rather than which subject they belong to. Ignoring the direction and nature of the relationship between items can easily lead to the wrong choice. Final Answer: History and Mathematics

Question 3

Find the odd group of letters from the following alternatives based on the step pattern of alphabetical positions.

Accepted Answer

Introduction / Context: This question tests your skill in recognizing and comparing step patterns in sequences of letters. Many reasoning questions in competitive exams involve such alphabet based patterns, so becoming comfortable with them is highly beneficial. Given Data / Assumptions: The letter groups given are: DGI, JMO, PRT, and TWY. You must select the group that does not follow the same step pattern as the others. Assume the standard mapping A = 1, B = 2, up to Z = 26. Concept / Approach: The idea is to examine the numerical positions of the letters in each group and then look at the differences between consecutive letters. If three groups exhibit a particular pattern, such as +3 then +2, and one group exhibits a different pattern, that different group is the odd one out. Step-by-Step Solution: Step 1: For DGI, the letters D, G, and I have positions 4, 7, and 9. From 4 to 7 is a jump of +3, and from 7 to 9 is a jump of +2. Step 2: For JMO, the letters J, M, and O have positions 10, 13, and 15. From 10 to 13 is +3 and from 13 to 15 is +2. So this group follows a +3, +2 pattern. Step 3: For TWY, the letters T, W, and Y have positions 20, 23, and 25. From 20 to 23 is +3, and from 23 to 25 is +2, once again showing the +3, +2 pattern. Step 4: For PRT, the letters P, R, and T have positions 16, 18, and 20. The difference from 16 to 18 is +2, and from 18 to 20 is +2, which forms a +2, +2 pattern, not +3, +2. Step 5: Since three groups follow a +3 then +2 sequence, while PRT follows +2 then +2, PRT is the odd group of letters. Verification / Alternative check: You can also visualize the letters on a number line of alphabet positions. Mark each triple and draw arrows showing the jumps. In DGI, JMO, and TWY, the arrows clearly have lengths corresponding to +3 and then +2. In PRT, both arrows are shorter and equal, clearly representing +2 and +2. This visualization confirms that PRT is structurally different from the others with respect to the step pattern. Why Other Options Are Wrong: DGI: Follows the +3, +2 step pattern and so matches JMO and TWY. JMO: Also exhibits a +3, +2 step between its letters, so it is not odd. TWY: Again follows the +3, +2 pattern and belongs to the main group. Common Pitfalls: Some candidates may wrongly focus on the actual letters instead of the step sizes, or they may check only one difference instead of both. As a result, they might miss the pattern entirely. A disciplined approach that always converts to numerical positions and computes all differences helps avoid such mistakes and leads to reliable answers. Final Answer: PRT

Question 4

Among the numbers 343, 64, 75 and 27, identify the odd number that is not a perfect cube.

Accepted Answer

Introduction / Context: In many aptitude and reasoning exams, you are often asked to find an odd item out from a set of numbers based on a hidden mathematical property. In this question, the hidden property is related to perfect cubes. A perfect cube is a number that can be written in the form n^3, where n is a whole number. By checking each option against this property, we can quickly see which number does not belong to the same group and therefore is the odd one out. Given Data / Assumptions: We are given four numbers: 343, 64, 75 and 27. We assume all numbers are positive integers. We are asked to find the number that does not share a common property with the others. The most natural property to test here is whether each number is a perfect cube. Concept / Approach: The key concept is the definition of a perfect cube. If a number N can be written as n^3 for some integer n, then N is a perfect cube. To solve the problem, we test each given number by seeing whether it equals the cube of an integer. If three of the numbers are perfect cubes and one is not, then the non cube is the odd one out. This is a very common pattern in odd number questions and appears frequently in competitive exams and placement tests. Step-by-Step Solution: Step 1: Check 343. We know 7^3 = 7 * 7 * 7 = 343, so 343 is a perfect cube. Step 2: Check 64. We know 4^3 = 4 * 4 * 4 = 64, so 64 is a perfect cube. Step 3: Check 27. We know 3^3 = 3 * 3 * 3 = 27, so 27 is a perfect cube. Step 4: Check 75. There is no integer n such that n^3 = 75. For example, 4^3 = 64 and 5^3 = 125, so 75 lies between two consecutive cubes and therefore is not a perfect cube. Step 5: Since 343, 64 and 27 are all perfect cubes but 75 is not, 75 is the number that does not fit the pattern. Verification / Alternative check: One quick way to verify is to look at nearby cubes. Between 4^3 = 64 and 5^3 = 125, there is no other perfect cube, so any number in that interval like 75 cannot be a cube. For the others, 3^3 = 27, 4^3 = 64 and 7^3 = 343 are well known standard cubes that appear frequently in cube tables. Because three numbers clearly match the cube pattern and one clearly does not, the conclusion is consistent. Why Other Options Are Wrong: 343 is not the odd one out because it is exactly equal to 7^3 and is therefore a perfect cube. 64 is not the odd one out because it is equal to 4^3 and satisfies the property of being a perfect cube. 27 is not the odd one out because it is equal to 3^3 and also satisfies the same property. Thus, these three numbers form a consistent group of perfect cubes. Common Pitfalls: Students sometimes look at last digits only and try to guess patterns without verifying the cube relationship properly. Another mistake is to search for factors or prime factorization patterns without first checking the simple and intended property of being a perfect cube. Time pressure in exams can also cause candidates to overlook known cube values like 343 and 64, so it is useful to memorize small cubes from 1^3 to at least 10^3. Final Answer: Therefore, the odd number that is not a perfect cube is 75.

Question 5

From the diseases Tetanus, Syphilis, Plague and Malaria, identify the odd one out based on the type of causative organism.

Accepted Answer

Introduction / Context: This question tests basic general knowledge about human diseases and their causative organisms. In many reasoning and aptitude tests, odd one out questions use medical or biological facts to check if the candidate can recognize subtle but important differences. Here, the four options are names of well known infectious diseases, and we need to decide which disease does not belong to the same group when classified by type of organism responsible for causing it. Given Data / Assumptions: The options are Tetanus, Syphilis, Plague and Malaria. All four are infectious diseases affecting humans. We classify them according to whether they are caused by bacteria or by some other kind of pathogen. Standard school level biology facts about these diseases are assumed. Concept / Approach: The central concept is the type of causative agent. Tetanus, Syphilis and Plague are bacterial diseases, each caused by a specific species of bacteria. Malaria, on the other hand, is not caused by bacteria but by protozoan parasites of the genus Plasmodium, which are transmitted by female Anopheles mosquitoes. To answer correctly, we recall or look up the nature of each disease, then group them based on bacterial versus non bacterial origin and identify the one that stands apart. Step-by-Step Solution: Step 1: Tetanus is caused by the bacterium Clostridium tetani that typically enters the body through contaminated wounds. So Tetanus is a bacterial disease. Step 2: Syphilis is caused by the bacterium Treponema pallidum and is mainly transmitted through sexual contact. So Syphilis is also a bacterial disease. Step 3: Plague is caused by the bacterium Yersinia pestis which is commonly transmitted by fleas that live on rodents. Therefore Plague is again a bacterial disease. Step 4: Malaria is caused by protozoan parasites, for example Plasmodium vivax or Plasmodium falciparum, which are single celled organisms that are not bacteria. They are transmitted by the bite of infected female Anopheles mosquitoes. Step 5: Thus three options are bacterial diseases, while Malaria is a protozoan disease, making Malaria the odd one out. Verification / Alternative check: A quick verification approach is to recall common biology classifications: Tetanus is listed under bacterial infections, Syphilis under bacterial sexually transmitted infections, and Plague under bacterial zoonotic diseases. Malaria is never placed under bacterial diseases in standard textbooks; it is always treated as a protozoan parasitic disease. Because this classification is stable and widely accepted, the conclusion that Malaria is the odd one out is reliable. Why Other Options Are Wrong: Tetanus is not the odd one out because it clearly belongs to the group of bacterial diseases caused by Clostridium species. Syphilis is not the odd one out because it is also caused by bacteria and fits well with the infectious bacterial group. Plague is not the odd one out for the same reason, as it is caused by Yersinia pestis, a bacterium, and shares a common pathogen type with Tetanus and Syphilis. Only Malaria differs because it is a protozoan parasitic disease. Common Pitfalls: One common mistake is to classify based on mode of transmission only, for example thinking Malaria is different because it is spread by mosquitoes while others are not. However Plague also involves an insect vector, so that reasoning is not robust. Another pitfall is to think of the severity or historic impact of the disease instead of the causative organism, which can lead to confusion. Focusing on the precise biological cause is the most reliable way to handle such questions in exams. Final Answer: The disease that is different in terms of causative organism and therefore the odd one out is Malaria.

Question 6

In the letter pairs QJ, SH, LN and UF, find the odd pair based on the sum of alphabetical positions.

Accepted Answer

Introduction / Context: Odd letter pair questions are very common in verbal reasoning sections of aptitude tests. Each pair of letters usually follows a particular pattern based on their positions in the English alphabet. The job of the candidate is to decode the pattern and identify which option does not follow it. In this question, we have four letter pairs and we need to spot the pair that breaks a consistent numerical relationship. Given Data / Assumptions: The given letter pairs are QJ, SH, LN and UF. We use the standard English alphabet with positions A = 1, B = 2, ..., Z = 26. We assume that the pattern is based on numerical operations like sum or difference on these positions. Concept / Approach: A natural way to analyze letter pair questions is to convert each letter to its alphabetical position and then test simple operations like sum, difference, or fixed gaps. Here, when we convert each pair and add the positions of the two letters, we find that three pairs yield the same total while one pair yields a different total. The pair with the different sum is the odd one out. This fixed sum property is a classic pattern in competitive exam questions. Step-by-Step Solution: Step 1: Convert QJ to positions. Q is the 17th letter and J is the 10th letter. Sum = 17 + 10 = 27. Step 2: Convert SH to positions. S is 19 and H is 8. Sum = 19 + 8 = 27. Step 3: Convert LN to positions. L is 12 and N is 14. Sum = 12 + 14 = 26. Step 4: Convert UF to positions. U is 21 and F is 6. Sum = 21 + 6 = 27. Step 5: We observe that QJ, SH and UF all have a sum of 27, while LN has a sum of 26. Step 6: Therefore LN does not follow the common pattern and is the odd letter pair. Verification / Alternative check: Another quick check is to note directly that in three of the options the sum is 27, a convenient number to remember because it is 3^3. Once we see the three equal sums, any different total is immediately suspicious and likely to be the odd one. No other simple pattern such as constant difference or mirror positions fits all four options as neatly, so the sum rule is clearly the intended logic. Why Other Options Are Wrong: QJ is not odd because 17 + 10 = 27, which matches the fixed sum pattern. SH is not odd because 19 + 8 = 27, again fitting the same pattern. UF is not odd because 21 + 6 = 27, so it also belongs to the same group. Only LN breaks the pattern with a sum of 26 and therefore must be the odd one out. Common Pitfalls: A frequent error is to focus only on the difference between letters instead of checking their sum. That may lead to confusion because the differences are not as revealing here. Another pitfall is guessing based on intuition about consonant combinations rather than doing the simple numerical conversion. To avoid such mistakes, it is good practice to routinely convert letters to numbers and systematically test both sums and differences for letter pair questions. Final Answer: The letter pair that breaks the constant sum pattern and is therefore the odd one out is LN.

Question 7

Among the numbers 5125, 8564, 7343 and 6216, identify the odd one out using the sum of digits property.

Accepted Answer

Introduction / Context: In number based odd one out questions, exam setters often hide a pattern in the digits of the numbers rather than in their overall magnitude. A very common and easy to test property is the sum of the digits. Sometimes the sum is prime for most numbers or divisible by a fixed value, and one number breaks that rule. In this question, we are given four four digit numbers and asked to find the one that does not follow the same digit sum pattern as the others. Given Data / Assumptions: The four numbers are 5125, 8564, 7343 and 6216. We consider the sum of digits of each number. A prime number is a positive integer greater than 1 that has no positive divisors other than 1 and itself. We assume the intended pattern is based on whether the digit sum is prime or composite. Concept / Approach: The approach is to find a property that is shared by three of the numbers and violated by one. Here, when we add the digits of each number, we will see that three sums are prime numbers, while one sum is not prime. The number whose digit sum is not prime will be the odd one out. Using the digit sum is especially convenient because it generates small numbers that are easy to classify as prime or composite. Step-by-Step Solution: Step 1: For 5125, compute the digit sum: 5 + 1 + 2 + 5 = 13. The number 13 is a prime number. Step 2: For 8564, compute the digit sum: 8 + 5 + 6 + 4 = 23. The number 23 is also a prime number. Step 3: For 7343, compute the digit sum: 7 + 3 + 4 + 3 = 17. The number 17 is again a prime number. Step 4: For 6216, compute the digit sum: 6 + 2 + 1 + 6 = 15. The number 15 is not prime because 15 = 3 * 5. Step 5: Three numbers have prime digit sums (13, 23 and 17), while 6216 has a composite digit sum (15). Therefore 6216 is the odd one out. Verification / Alternative check: After identifying 6216 as the candidate, we can quickly recheck the calculations to avoid arithmetic mistakes. Digit sums 13, 23 and 17 are all well known prime numbers, and 15 is clearly divisible by 3 and 5. No other simple and consistent pattern involving divisibility or parity fits all four numbers as clearly as the digit sum prime versus composite rule, so this logic is very likely the intended one. Why Other Options Are Wrong: 5125 is not odd because its digit sum 13 is a prime number, fitting the common pattern. 8564 is not odd because its digit sum 23 is also prime and matches the same rule. 7343 is not odd because its digit sum 17 is again prime and belongs to the same group. Only 6216 has a composite digit sum, so it must be the odd one out. Common Pitfalls: Students sometimes attempt complex factorization of the full four digit numbers instead of starting with simple digit based checks. Another mistake is to check only divisibility by 2, 3 or 5 on the whole number, which may not reveal any clear pattern here. Remember that for odd one out questions, testing digit sums, parity and small factor patterns often leads to quick and reliable answers. Final Answer: The number whose digit sum is not prime and therefore the odd one out is 6216.

Question 8

Among the numbers 529, 549, 731 and 525, identify the odd one out based on the property of perfect squares.

Accepted Answer

Introduction / Context: This question belongs to the common category of odd one out problems where the hidden pattern is based on special number types such as squares, cubes, primes or multiples. Here, the natural property to inspect is whether each number is a perfect square. A perfect square is a number that can be expressed as n^2 for some integer n. By checking this property for each option, we can easily recognize which number stands apart from the rest. Given Data / Assumptions: The numbers given are 529, 549, 731 and 525. We test whether each number is a perfect square. We use basic square values and simple multiplication to identify perfect squares. Concept / Approach: The idea is to recall or compute squares of integers around the size of the given numbers. Squares near 500 to 800 include 22^2 = 484, 23^2 = 529, 24^2 = 576 and 25^2 = 625. If one of the numbers matches any of these exactly, it is a perfect square, while the others are not. The unique one in this sense becomes the odd one out. This style of question encourages candidates to be comfortable with basic square tables for quick mental reasoning. Step-by-Step Solution: Step 1: 23^2 = 23 * 23 = 529. So 529 is a perfect square. Step 2: Check 549. It lies between 23^2 = 529 and 24^2 = 576, but it does not equal any n^2, so 549 is not a perfect square. Step 3: Check 731. It lies between 27^2 = 729 and 28^2 = 784, and it is not equal to any exact square value, so 731 is not a perfect square. Step 4: Check 525. It lies between 22^2 = 484 and 23^2 = 529 and again does not match any perfect square value. Step 5: Therefore, 529 is the only perfect square among the four numbers, making it the odd one out. Verification / Alternative check: We can reconfirm by factoring. For 529, we can test divisibility by 23 and find 529 = 23 * 23, confirming it is a perfect square. For 549, 731 and 525, factorization does not produce equal integer factors of the same value, so they cannot be written as n^2. This double check ensures that our identification of 529 as the only perfect square is accurate. Why Other Options Are Wrong: 549 is not the odd one out because although it is not a perfect square, so are 731 and 525, so it shares the non square property with others. 731 is not the odd one out because it is also not a perfect square and behaves similarly to 549 and 525 in this respect. 525 is not the odd one out because it is again a non square number. 529 is special and different because it is exactly 23^2. Common Pitfalls: A common error is to guess based on the last digit alone without checking full squares properly. For example, noticing that 529 ends with 9 and thinking several others might also be squares without verification. Some candidates attempt to test divisibility by small primes only, which may not clearly indicate that a number is a perfect square. Memorizing squares from 1^2 to at least 30^2 greatly speeds up such questions and reduces mistakes in time pressured exams. Final Answer: The only perfect square in the list and therefore the odd one out is 529.

Question 9

Among the months MARCH, MAY, JUNE and DECEMBER, identify the odd one out based on the number of days.

Accepted Answer

Introduction / Context: Calendar based odd one out questions are standard in verbal reasoning and general awareness sections. These questions rely on basic facts about months, such as the number of days in each month or their position in the year. In this problem, four month names are given, and we must select the one that differs from the others according to the number of days in that month. Given Data / Assumptions: The months given are March, May, June and December. We use the standard Gregorian calendar. March, May and December each have 31 days. June has 30 days. Concept / Approach: The key concept here is the distribution of 30 day and 31 day months in a year. March, May, July, August, October and December all have 31 days, while April, June, September and November have 30 days. February is special with 28 or 29 days. By checking each option against this rule, we can quickly see which month does not match the others in terms of day count. The month with 30 days among mostly 31 day months will be the odd one out. Step-by-Step Solution: Step 1: March is a 31 day month. Step 2: May is a 31 day month. Step 3: December is also a 31 day month. Step 4: June is a 30 day month, which is different from the others listed. Step 5: Since three of the months have 31 days and one month has 30 days, that one month is the odd one out. So June is the answer. Verification / Alternative check: You can recollect the common mnemonic knuckle rule or the rhyme used to remember the day count of each month. In every version of this memory aid, June consistently appears as a 30 day month. March, May and December are always confirmed as 31 day months. Because this is a fixed feature of the calendar, there is no ambiguity in the classification. Why Other Options Are Wrong: March is not the odd one out because its 31 day count matches that of May and December. May is not the odd one out because it also has 31 days and belongs to the same group as March and December. December is not the odd one out because it too has 31 days. Only June differs because it has 30 days, making it the odd one. Common Pitfalls: Some candidates focus on the position in the year, such as thinking December is different because it is the last month, forgetting that the question is about a more basic property. Others may confuse months with 30 and 31 days if they have not revised the calendar properly. Reviewing the months and their day counts before exams helps avoid simple but costly mistakes in such questions. Final Answer: The only month among the options that has 30 days and is therefore the odd one out is JUNE.

Question 10

In the pairs 1 : 8, 27 : 64, 125 : 218 and 323 : 512, find the odd pair based on perfect cube patterns.

Accepted Answer

Introduction / Context: Odd one out questions using number pairs often hide patterns related to squares, cubes or sequences. Each pair may represent related mathematical values such as consecutive powers or values in a numerical progression. In this problem, each option is a pair of numbers separated by a colon, and we must identify which pair does not fit the pattern that the other pairs follow. The pattern here is based on perfect cubes in the first component of each pair. Given Data / Assumptions: The given pairs are 1 : 8, 27 : 64, 125 : 218 and 323 : 512. We use standard cube values of small integers. We focus first on the first number in each pair and check whether it is a perfect cube. Concept / Approach: The main concept is the idea of perfect cubes. A number n^3, where n is an integer, is called a perfect cube. We recognize standard cubes such as 1^3 = 1, 2^3 = 8, 3^3 = 27, 4^3 = 64 and 5^3 = 125. When we examine the pairs, we notice that in three of them, the first number is clearly a perfect cube, but in one pair it is not. That pair is the odd one out. While the second numbers also relate to cubes, the simplest and most consistent pattern here is present in the first number of each pair. Step-by-Step Solution: Step 1: For 1 : 8, the first number 1 is 1^3, so it is a perfect cube. Step 2: For 27 : 64, the first number 27 is 3^3, so it is also a perfect cube. Step 3: For 125 : 218, the first number 125 is 5^3, which is again a perfect cube. Step 4: For 323 : 512, the first number 323 is not a perfect cube. 6^3 = 216 and 7^3 = 343, so 323 lies between these cubes and does not match any n^3. Step 5: Therefore, three pairs have a perfect cube as their first element, whereas the pair 323 : 512 does not, making it the odd one out. Verification / Alternative check: We can verify by writing out the first numbers in factorized form. 1 = 1 * 1 * 1, 27 = 3 * 3 * 3 and 125 = 5 * 5 * 5 are clear cubes. For 323, we can try nearby cubes: 6^3 = 216 and 7^3 = 343, neither equal to 323, confirming that 323 is not a cube. The second numbers 8, 64 and 512 are themselves cubes of 2, 4 and 8 respectively, which supports the idea that the question is built around cube patterns. Why Other Options Are Wrong: 1 : 8 is not the odd pair because the first number 1 is a perfect cube and fits the cube based pattern. 27 : 64 is not the odd pair because 27 is also a perfect cube and aligns with the same logic. 125 : 218 is not the odd pair because 125 is again a perfect cube and behaves similarly to 1 and 27 in this context. Only in 323 : 512 is the first number not a perfect cube, which sets it apart. Common Pitfalls: Many candidates get distracted by the second numbers or by minor differences like 218 instead of 216, and search for very complex relationships between both members of each pair. Another mistake is to ignore cube values above 5^3 or 6^3, which makes it harder to quickly categorize numbers like 323. Remember that exam setters often use well known cube numbers such as 1, 27 and 125 to signal the underlying pattern, so recognizing these early can save valuable time. Final Answer: The pair whose first number is not a perfect cube and is therefore the odd one out is 323 : 512.

Question 11

From the letter pairs MG, QK, VN and UO, find the odd pair based on the fixed gap between letters.

Accepted Answer

Introduction / Context: Letter pair questions often hide a simple numeric relationship between the positions of the two letters in the alphabet. Typical relationships include a fixed forward or backward gap. To solve such questions efficiently, candidates must convert letters to numeric positions and then look for a consistent pattern. In this problem, we are given four pairs of letters and asked to find which pair does not follow the same positional gap rule as the others. Given Data / Assumptions: The letter pairs are MG, QK, VN and UO. We take A = 1, B = 2, ..., Z = 26 as the positions in the English alphabet. We compare the difference between the first and second letters in each pair. Concept / Approach: The primary concept is the fixed difference between letter positions. We calculate the difference first letter position minus second letter position, or simply the absolute difference, and check whether most pairs share the same value. If three pairs have the same difference (for example 6) and one has a different difference (for example 8), the pair with the different gap is the odd one out. This kind of pattern is common in reasoning sections and is easy to handle once you practice converting letters to numeric positions quickly. Step-by-Step Solution: Step 1: For MG, M is the 13th letter and G is the 7th letter. Difference = 13 - 7 = 6. Step 2: For QK, Q is the 17th letter and K is the 11th letter. Difference = 17 - 11 = 6. Step 3: For UO, U is the 21st letter and O is the 15th letter. Difference = 21 - 15 = 6. Step 4: For VN, V is the 22nd letter and N is the 14th letter. Difference = 22 - 14 = 8. Step 5: Three pairs have a fixed difference of 6, while one pair has a difference of 8. Therefore VN is the pair that breaks the pattern. Verification / Alternative check: We can quickly recheck each position to avoid errors: positions M = 13, G = 7, Q = 17, K = 11, V = 22, N = 14, U = 21 and O = 15 are standard. Recomputing confirms differences: MG has 6, QK has 6, UO has 6 and VN has 8. Since these are straightforward arithmetic operations, the pattern is robust and unambiguous. Why Other Options Are Wrong: MG is not the odd one out because it satisfies the common difference rule of 6. QK is not the odd one out because it also has a difference of 6 and belongs to the same group. UO is not the odd one out because its letter difference is again 6, consistent with MG and QK. Only VN has a different positional gap of 8, so it is the odd member. Common Pitfalls: A common mistake is to look for alphabetical order direction (forward or backward) only, ignoring the actual magnitude of the gap. Some candidates may try to form meaningful abbreviations or words out of the pairs instead of checking the numeric pattern, which is not the intent in such reasoning questions. Systematically converting letters to numbers and immediately testing small differences like 2, 3, 4 or 6 helps solve these quickly and accurately. Final Answer: The letter pair that does not follow the fixed gap of 6 and is therefore the odd one out is VN.

Question 12

Among the numbers 4267, 2498, 2739 and 5496, identify the odd one out using divisibility by 11.

Accepted Answer

Introduction / Context: In many aptitude tests, odd one out number questions use divisibility rules as the underlying pattern, especially rules for 3, 9 or 11. Here we have four seemingly unrelated four digit numbers and must decide which one differs from the others. A useful approach is to check divisibility by specific numbers using known digit based rules, rather than performing full division each time. Given Data / Assumptions: The given numbers are 4267, 2498, 2739 and 5496. We apply the standard divisibility rule for 11. Divisibility by 11 can be tested by taking the difference between the sum of digits in odd positions and the sum of digits in even positions. If this difference is 0 or a multiple of 11, the number is divisible by 11. Concept / Approach: The divisibility test for 11 is very powerful when dealing with multi digit numbers. For a four digit number abcd, we compute (a + c) minus (b + d). If the result is 0, 11, -11 and so on, then the number is divisible by 11. In this question, when we apply this rule to each of the four numbers, three of them will fail the test and one will satisfy it. The one divisible by 11 will be the odd one out, because it has a special divisibility property that the others lack. Step-by-Step Solution: Step 1: For 4267, digits are 4, 2, 6 and 7. Sum of first and third digits = 4 + 6 = 10. Sum of second and fourth digits = 2 + 7 = 9. Difference = 10 - 9 = 1, not a multiple of 11. So 4267 is not divisible by 11. Step 2: For 2498, digits are 2, 4, 9 and 8. Sum of first and third digits = 2 + 9 = 11. Sum of second and fourth digits = 4 + 8 = 12. Difference = 11 - 12 = -1, not a multiple of 11. So 2498 is not divisible by 11. Step 3: For 2739, digits are 2, 7, 3 and 9. Sum of first and third digits = 2 + 3 = 5. Sum of second and fourth digits = 7 + 9 = 16. Difference = 5 - 16 = -11, which is a multiple of 11. So 2739 is divisible by 11. Step 4: For 5496, digits are 5, 4, 9 and 6. Sum of first and third digits = 5 + 9 = 14. Sum of second and fourth digits = 4 + 6 = 10. Difference = 14 - 10 = 4, not a multiple of 11. So 5496 is not divisible by 11. Step 5: Therefore 2739 alone is divisible by 11, making it the odd one out. Verification / Alternative check: As an additional check, we can perform short division: 2739 divided by 11 equals 249 exactly, so 11 * 249 = 2739 confirms divisibility. For the other numbers, dividing by 11 does not yield an integer, which reinforces the result from the digit test. No other simple pattern, such as digit sum or parity, produces as clear and unique a distinction as divisibility by 11, so this is the intended logic. Why Other Options Are Wrong: 4267 is not the odd one out because it fails the divisibility by 11 test, like 2498 and 5496. 2498 is not the odd one out for the same reason; it is not divisible by 11 and shares this property with 4267 and 5496. 5496 also fails the test and so cannot be singled out on this basis. Only 2739 passes the 11 divisibility test, so it is different from all the others. Common Pitfalls: A common mistake is to check only divisibility by 2 or 5, which does not create a unique classification in this set. Another pitfall is to try to factor each number fully, which is more time consuming than using the digit rule for 11. Learning and practicing divisibility rules for 3, 9 and 11 is very useful for quickly tackling number based reasoning questions in competitive exams. Final Answer: The only number divisible by 11 and therefore the odd one out is 2739.

Question 13

From the numbers 8912, 3469, 5555 and 6734, identify the odd one out using a divisibility by 11 pattern.

Accepted Answer

Introduction / Context: Odd one out questions with four digit numbers often rely on recognizable digit patterns or simple divisibility rules. In this problem, the four options look quite different at first glance, but one of them has a fundamental numerical property that the others lack. We can either notice the pattern by observation or confirm it using a divisibility test. Two simple clues are that 5555 has all digits the same and that it satisfies the test for divisibility by 11. Given Data / Assumptions: The numbers are 8912, 3469, 5555 and 6734. We check both digit pattern and divisibility by 11. We use the standard divisibility rule for 11 based on alternating sums of digits. Concept / Approach: There are two supporting concepts here. First, 5555 has all four digits identical, while the other numbers do not, which already makes it visually distinct. Second, the divisibility rule for 11 states that for a number abcd, we compute (a + c) minus (b + d). If the result is 0 or a multiple of 11, the number is divisible by 11. When we apply this rule, we find that only 5555 is divisible by 11, which gives a clear mathematical justification for it being the odd one out. Step-by-Step Solution: Step 1: Note that 5555 has a special pattern where all digits are 5, unlike the mixed digit patterns in 8912, 3469 and 6734. Step 2: Apply the rule for 11 to 8912. Sum of first and third digits = 8 + 1 = 9. Sum of second and fourth digits = 9 + 2 = 11. Difference = 9 - 11 = -2, not a multiple of 11, so 8912 is not divisible by 11. Step 3: For 3469, sum of first and third digits = 3 + 6 = 9. Sum of second and fourth digits = 4 + 9 = 13. Difference = 9 - 13 = -4, not a multiple of 11. Step 4: For 5555, sum of first and third digits = 5 + 5 = 10. Sum of second and fourth digits = 5 + 5 = 10. Difference = 10 - 10 = 0, which is a multiple of 11, so 5555 is divisible by 11. Step 5: For 6734, sum of first and third digits = 6 + 3 = 9. Sum of second and fourth digits = 7 + 4 = 11. Difference = 9 - 11 = -2, not a multiple of 11. Step 6: Therefore, 5555 alone is divisible by 11 and also visually distinct by having all identical digits, so it is the odd one out. Verification / Alternative check: We can confirm by direct division: 5555 divided by 11 equals 505, an integer, which proves divisibility. For 8912, 3469 and 6734, division by 11 does not give integer results, consistent with the digit rule. The repeated digit pattern in 5555 reinforces its uniqueness even without performing detailed calculations. Why Other Options Are Wrong: 8912 is not the odd one out because it is not divisible by 11 and has mixed digits like 3469 and 6734. 3469 is not the odd one out because it also fails the 11 divisibility test and does not show any special digit repetition. 6734 is not the odd one out because it follows the same pattern as 8912 and 3469 with mixed digits and no divisibility by 11. 5555 stands apart both in digit pattern and divisibility, so the other three numbers form a natural group when compared against it. Common Pitfalls: Some students may focus only on the visual clue of repeated digits and ignore the confirmation by divisibility, which is acceptable but less rigorous. Others might wrongly assume there is a more complicated arithmetic pattern when a simple rule suffices. Developing the habit of checking straightforward divisibility rules avoids overcomplicating such questions and saves time in competitive exams. Final Answer: The number that is divisible by 11 and also has all digits equal, and is therefore the odd one out, is 5555.

Question 14

In the letter pairs TP, DH, WS and RN, find the odd pair based on whether the sequence is ascending or descending.

Accepted Answer

Introduction / Context: Letter pair questions in reasoning exams often test your understanding of alphabetical order and direction. In many such problems, most pairs either move forward or backward in the alphabet by a fixed number of positions, and one pair reverses that direction. In this question, we are given four letter pairs and asked to find the one that behaves differently in terms of alphabetical order direction. Given Data / Assumptions: The letter pairs are TP, DH, WS and RN. We map letters to their positions in the alphabet: A = 1, B = 2, ..., Z = 26. We look at whether the second letter comes before or after the first letter in alphabetical order. Concept / Approach: The key concept here is direction of movement. For each pair, we compare the positions of the first and second letters. If the second letter has a smaller position value than the first, the pair is in descending order. If the second letter has a larger position value than the first, the pair is in ascending order. When we apply this to all four pairs, we find that three are descending and one is ascending, which reveals the odd one out. Step-by-Step Solution: Step 1: For TP, T is the 20th letter and P is the 16th letter. Since 16 is less than 20, P comes before T in the alphabet, so this pair is descending. Step 2: For DH, D is the 4th letter and H is the 8th letter. Since 8 is greater than 4, H comes after D in the alphabet, so this pair is ascending. Step 3: For WS, W is the 23rd letter and S is the 19th letter. Since 19 is less than 23, S comes before W, so WS is descending. Step 4: For RN, R is the 18th letter and N is the 14th letter. Since 14 is less than 18, N comes before R, making RN descending. Step 5: Three pairs TP, WS and RN are descending, whereas DH is ascending. Therefore DH is the odd one out. Verification / Alternative check: We can recheck the positions for accuracy: D = 4, H = 8, T = 20, P = 16, W = 23, S = 19, R = 18 and N = 14. Comparing each pair confirms that only DH moves from a lower to a higher alphabetical position. Because this direction based rule is simple and consistent, it is very likely the intended pattern for exam purposes. Why Other Options Are Wrong: TP is not the odd one out because it follows a descending pattern from T to P. WS is not the odd one out because it also follows a descending pattern from W to S. RN is not the odd one out because it again moves from a higher letter R to a lower letter N. DH is different from all three because its order is ascending from D to H. Common Pitfalls: Some candidates may focus only on the size of the difference between letters and ignore the direction, which is not the important feature here. Others might try to find meaningful abbreviations or words, which is usually not the aim in such abstract reasoning problems. The safest approach for letter pair questions is to systematically evaluate both the numerical gap and the direction, then look for which property forms a consistent pattern across options. Final Answer: The only letter pair that is in ascending alphabetical order and is therefore the odd one out is DH.

Question 15

Among the three digit numbers 431, 936, 871 and 652, identify the odd one out based on the order of digits.

Accepted Answer

Introduction / Context: In digit pattern problems, the odd one out is often found by observing the order of digits within each number. The digits might be strictly increasing, strictly decreasing or follow some other simple relation. In this question, four three digit numbers are given and we must identify which one has a different internal order of digits compared to the others. Given Data / Assumptions: The numbers are 431, 936, 871 and 652. We treat each number as a sequence of three digits. We compare whether the digits from left to right form a strictly decreasing order. Concept / Approach: The key idea is to check each number for monotonically decreasing digits, that is, each subsequent digit must be smaller than the previous one. If three numbers have digits in strictly decreasing order and one number does not, the one that breaks this rule is the odd one out. Such descending order patterns are very common in number series and odd one out questions. Step-by-Step Solution: Step 1: For 431, the digits are 4, 3 and 1. We see that 4 > 3 and 3 > 1, so the digits are strictly decreasing. Step 2: For 936, the digits are 9, 3 and 6. 9 > 3, but 3 is not greater than 6. Here the sequence goes down from 9 to 3, then up from 3 to 6, so it is not strictly decreasing. Step 3: For 871, the digits are 8, 7 and 1. Since 8 > 7 and 7 > 1, this sequence is strictly decreasing. Step 4: For 652, the digits are 6, 5 and 2. We have 6 > 5 and 5 > 2, so this is also strictly decreasing. Step 5: Three numbers 431, 871 and 652 have digits in strictly decreasing order, while 936 breaks this pattern. Therefore 936 is the odd one out. Verification / Alternative check: We can verify again by quickly writing the inequality chain for each number: 4 > 3 > 1, 9 > 3 < 6, 8 > 7 > 1, 6 > 5 > 2. Only for 936 does the chain not show continuous decreasing order, which confirms our reasoning. No other simple digit based pattern, such as sums or products of digits, gives as clear a distinction as the order comparison here. Why Other Options Are Wrong: 431 is not the odd one out because its digits follow a perfect decreasing sequence. 871 is not the odd one out because it also has strictly decreasing digits. 652 is not the odd one out because it shares the same decreasing order property. 936 is alone in not having a monotonic decrease, which makes it different. Common Pitfalls: A typical mistake is to focus on the overall magnitude or divisibility of the numbers instead of the internal digit pattern. Some candidates may misread digits quickly under time pressure and miss the increase from 3 to 6 in 936. Practicing with digit order patterns helps in quickly spotting such irregularities in competitive exams. Final Answer: The number whose digits do not form a strictly decreasing sequence and is therefore the odd one out is 936.

Question 16

In the four digit numbers 5210, 7214, 9218 and 7426, find the odd one out based on a double of the first digit pattern.

Accepted Answer

Introduction / Context: Some odd one out questions hide a neat arithmetic pattern relating specific digits within each number. Here, each number has four digits and we can think of it as abcd. A common type of pattern relates the first digit to the last two digits, for example the last two digits may equal twice the first digit. If three numbers follow this rule and one fails, the one that fails is the odd one out. This question is a classic example of that kind of digit relationship puzzle. Given Data / Assumptions: The numbers are 5210, 7214, 9218 and 7426. We interpret each number as a four digit sequence abcd. We test whether the last two digits form a number equal to 2 times the first digit. Concept / Approach: Let the first digit be a and the last two digits together be a two digit number k. In three of the numbers, k equals 2 * a. For example, if a = 5, then twice the first digit is 10 and the last two digits are 10. The number in which this relationship does not hold is the odd one out. This pattern is simple yet effective in reasoning exams because it forces candidates to connect different parts of the number rather than treat it as a whole. Step-by-Step Solution: Step 1: Consider 5210. The first digit is 5 and the last two digits are 10. Twice the first digit is 2 * 5 = 10, which matches the last two digits. Step 2: Consider 7214. The first digit is 7 and the last two digits are 14. Twice the first digit is 2 * 7 = 14, again matching the last two digits. Step 3: Consider 9218. The first digit is 9 and the last two digits are 18. Twice the first digit is 2 * 9 = 18, which also matches the last two digits. Step 4: Consider 7426. The first digit is 7 and the last two digits are 26. Twice the first digit is 2 * 7 = 14, which does not match 26. Step 5: Therefore, 5210, 7214 and 9218 follow the pattern last two digits = 2 * first digit, while 7426 does not. So 7426 is the odd one out. Verification / Alternative check: We can check the middle digit for completeness, but it is not needed for this pattern and does not affect the rule. Recomputing twice the first digit for each number confirms that only 7426 breaks the relationship. Since the pattern is exact and simple arithmetic, the conclusion is secure. Why Other Options Are Wrong: 5210 is not the odd one out because it perfectly satisfies the pattern 2 * first digit = last two digits. 7214 is not the odd one out because it also obeys the same rule. 9218 is not the odd one out because its last two digits equal twice the first digit. 7426 alone fails this rule, which makes it different. Common Pitfalls: A common mistake is to focus only on the sum or product of all four digits instead of exploring targeted relationships, such as first digit to last two digits. Another error is to treat the last two digits separately rather than as a two digit number, which hides the intended pattern. Carefully checking simple linear relationships between digits is an efficient strategy for such reasoning questions. Final Answer: The number that does not satisfy the rule last two digits = double the first digit and is therefore the odd one out is 7426.

Question 17

Among Arithmetic, Mathematics, Geometry and Algebra, identify the odd term based on the hierarchy of mathematical topics.

Accepted Answer

Introduction / Context: This odd one out question is based on basic classification of mathematical topics. Three of the given terms are names of branches or subfields within mathematics, while one term is the name of the overall subject itself. The candidate needs to understand the hierarchy: general subject versus its components. Such classification questions are common in verbal reasoning and general mental ability sections of exams. Given Data / Assumptions: The four terms are Arithmetic, Mathematics, Geometry and Algebra. Mathematics is the broad subject that includes several branches. Arithmetic, Geometry and Algebra are all considered branches or components of Mathematics. Concept / Approach: The conceptual approach is to identify which word is of a higher level in the classification hierarchy. Mathematics is the overarching discipline that encompasses many subfields including Arithmetic, Algebra, Geometry, Calculus and others. In contrast, Arithmetic, Geometry and Algebra are specific branches dealing with particular kinds of problems and concepts. The item that is not at the same level as the others is the odd one out. Step-by-Step Solution: Step 1: Recognize that Mathematics is the general name of the subject that covers numerical, algebraic, geometric and many other types of study. Step 2: Arithmetic is the branch of Mathematics that deals primarily with basic operations on numbers like addition, subtraction, multiplication and division. Step 3: Geometry is the branch of Mathematics that focuses on shapes, sizes, properties of figures and spatial relationships. Step 4: Algebra is the branch of Mathematics that studies symbols, variables and equations and how they relate through rules and operations. Step 5: Since Arithmetic, Geometry and Algebra are all subfields under the larger umbrella of Mathematics, while Mathematics itself is the entire field, Mathematics is the odd term out. Verification / Alternative check: We can cross check by considering curriculum structure. School and college syllabi usually list Mathematics as the subject and then list topics such as Arithmetic, Algebra and Geometry underneath it. No standard syllabus lists Mathematics as a subfield under any of the other three terms, which confirms that Mathematics is at a higher level. This hierarchical relationship clearly separates Mathematics from the other three items. Why Other Options Are Wrong: Arithmetic is not the odd one out because it is a branch of Mathematics and is parallel in status to Geometry and Algebra. Geometry is not the odd one out because it is also a branch of Mathematics and stands alongside Arithmetic and Algebra as a component area. Algebra is not the odd one out because it too is a branch within the wider subject of Mathematics. Mathematics differs from these because it is the general name for the entire subject, not a single branch. Common Pitfalls: Some test takers may focus on apparent difficulty level and incorrectly feel that Algebra or Geometry is different because it involves more advanced abstract thinking, but difficulty is not the classification criterion here. Others may mistakenly treat Arithmetic as basic and separate it, when in fact it is clearly an internal part of Mathematics just like the other branches. Whenever you see related academic terms, it is useful to think in terms of general subject versus subtopics to correctly answer such questions. Final Answer: The only term that represents the overall subject instead of a branch, and is therefore the odd one out, is Mathematics.

Question 18

In the letter sequences ACEG, BDFG, JLNP and SUWY, identify the odd sequence based on equal spacing of letters.

Accepted Answer

Introduction / Context: Letter sequence odd one out questions typically rely on a constant step or gap between consecutive letters in the alphabet. Three sequences maintain the same gap throughout, while one sequence contains a break in that pattern. In this problem, we are given four sequences of four letters each and asked to detect the sequence that does not maintain a consistent step size between letters. Given Data / Assumptions: The sequences are ACEG, BDFG, JLNP and SUWY. We map letters to positions: A = 1, B = 2, ..., Z = 26. We examine the difference between consecutive letters in each sequence. Concept / Approach: The central concept is constant spacing. In a well structured sequence, each pair of consecutive letters has the same alphabetical gap, for example a gap of 2: A, C, E, G. To solve the question, we compute the difference in positions between each pair of neighboring letters in every sequence. If three sequences maintain a constant difference of 2 and one sequence deviates from this, the deviating one is the odd sequence. Step-by-Step Solution: Step 1: For ACEG, positions are A = 1, C = 3, E = 5, G = 7. Differences are 3 - 1 = 2, 5 - 3 = 2 and 7 - 5 = 2. So ACEG has a constant gap of 2. Step 2: For BDFG, positions are B = 2, D = 4, F = 6, G = 7. Differences are 4 - 2 = 2, 6 - 4 = 2 and 7 - 6 = 1. The last gap is 1, not 2, so the pattern breaks. Step 3: For JLNP, positions are J = 10, L = 12, N = 14, P = 16. Differences are 12 - 10 = 2, 14 - 12 = 2 and 16 - 14 = 2. Constant gap of 2 is maintained. Step 4: For SUWY, positions are S = 19, U = 21, W = 23, Y = 25. Differences are 21 - 19 = 2, 23 - 21 = 2 and 25 - 23 = 2. Again we have a constant difference of 2. Step 5: ACEG, JLNP and SUWY have a uniform spacing of 2, while BDFG does not, so BDFG is the odd sequence. Verification / Alternative check: By simply writing the sequences in alphabet order with indices, we can visually inspect the jumps and confirm that only BDFG has a smaller final jump. No other straightforward rule such as reverse order or mixed gaps fits all sequences as neatly as the constant gap rule. Therefore, the constant step pattern is the intended logic for this question. Why Other Options Are Wrong: ACEG is not the odd sequence because it follows the 2 step pattern completely. JLNP is not the odd sequence because it also maintains a constant gap of 2 between all letters. SUWY is not the odd sequence because it continues the same step size of 2 throughout. BDFG is different because its last jump from F to G is only 1 step, breaking the uniform spacing. Common Pitfalls: Some candidates may only check the first two gaps in each sequence and overlook a later break in the pattern, as happens in BDFG. Others may try to find meaning in the sequences as abbreviations rather than as abstract letter progressions. To avoid mistakes, always compute all the gaps in every sequence and confirm that the pattern holds from start to end. Final Answer: The letter sequence that does not maintain a constant gap of 2 and is therefore the odd one out is BDFG.

Question 19

Among the pairs (16, 32), (20, 40), (64, 81) and (81, 162), identify the odd pair based on the relationship between the two numbers.

Accepted Answer

Introduction / Context: This question presents four ordered pairs of numbers and asks us to find the odd one out. A natural idea is to check whether there is a simple multiplicative relationship between the first and second numbers in each pair. In many aptitude tests, the most common relationship is that the second number is double the first number. If three pairs follow this rule and one does not, the pair that breaks the rule is the odd one out. Given Data / Assumptions: The given pairs are (16, 32), (20, 40), (64, 81) and (81, 162). We test whether the second number equals 2 times the first number. All numbers are positive integers. Concept / Approach: The core concept is the doubling relationship. If in a pair (a, b) we have b = 2 * a, then the second number is exactly twice the first. We compute this relationship for each pair. If three pairs satisfy b = 2 * a and one pair does not, then the one pair that fails the condition is the odd one out. This is a direct and easily tested pattern and is typically what exam setters intend when they give such simple number pairs. Step-by-Step Solution: Step 1: For (16, 32), 2 * 16 = 32, so the second number is double the first. Step 2: For (20, 40), 2 * 20 = 40, so this pair also satisfies the doubling rule. Step 3: For (81, 162), 2 * 81 = 162, so this pair again follows the same rule. Step 4: For (64, 81), 2 * 64 = 128, which is not equal to 81. Thus, this pair does not obey the doubling relationship. Step 5: Therefore, (64, 81) is the only pair that does not have the second number equal to twice the first number and is the odd one out. Verification / Alternative check: An alternative way to think is in terms of ratios. For the first, second and fourth pairs, the ratio b / a equals 2, while for (64, 81), the ratio 81 / 64 is greater than 1 but not equal to 2. This confirms that the multiplicative pattern is broken only in the third pair. No other simple relationship such as difference or sum works so neatly for three pairs and fails for only one, so doubling is clearly the intended logic. Why Other Options Are Wrong: (16, 32) is not the odd one out because 32 is exactly double 16 and fits the main pattern. (20, 40) is not the odd one out because 40 is exactly double 20, again consistent with the pattern. (81, 162) is not the odd one out because 162 is exactly double 81 and follows the same rule. Only (64, 81) fails the condition second equals twice the first, which makes it different. Common Pitfalls: Some candidates may be distracted by the fact that 64 and 81 are themselves perfect squares (8^2 and 9^2) and look for a square based pattern, but the exam setter here is focusing on the relation between the two members of each pair. Others may try to match differences between numbers instead of ratios, which does not reveal as clean a pattern in this set. When you see number pairs where three are simple multiples and one is not, always test for the multiplicative relationship first. Final Answer: The pair in which the second number is not double the first and is therefore the odd one out is (64, 81).

Question 20

Among Aizawl, Agartala, Shillong and Darjeeling, identify the odd place based on whether it is a state capital or not.

Accepted Answer

Introduction / Context: This odd one out question comes from basic Indian geography and general knowledge. Competitive exams often test whether the learner can quickly recognize state capitals and distinguish them from other important but non capital cities or hill stations. Here we are given four well known places from the northeastern part of India and asked to pick the one that does not belong with the others when we classify them as state capitals versus non capitals. Given Data / Assumptions: The four places given are Aizawl, Agartala, Shillong and Darjeeling. All four are cities or hill stations located in or near the northeastern region of India. We use standard and widely accepted information about Indian state capitals. We assume that the intended classification is based on which places are state capitals and which are not. Concept / Approach: The concept is simple classification by administrative status. Some cities are designated as state capitals and host the main offices of the state government, while others may still be famous but do not have capital status. In this question, three of the places are capitals of northeastern states of India, while one place is a famous hill station that does not serve as the capital of any state. The non capital city is therefore the odd one out in this set. Step-by-Step Solution: Step 1: Aizawl is the capital city of the state of Mizoram in northeastern India. Step 2: Agartala is the capital city of the state of Tripura, also located in the northeastern region. Step 3: Shillong is the capital city of the state of Meghalaya and is a well known hill station as well. Step 4: Darjeeling, although very famous for its tea gardens and cool climate, is a hill station in West Bengal and not the capital city of any Indian state. The capital of West Bengal is Kolkata. Step 5: Therefore, Aizawl, Agartala and Shillong form a group of state capitals, while Darjeeling does not share this property. Verification / Alternative check: A quick verification can be done by recalling or checking a standard list of Indian state capitals where Mizoram, Tripura and Meghalaya clearly list Aizawl, Agartala and Shillong as their capitals respectively. When looking at West Bengal, Darjeeling appears as a tourist town and hill station, while Kolkata is shown as the capital city. Since the administrative role of each city is well defined and does not change frequently, this classification is reliable for exam purposes. Why Other Options Are Wrong: Aizawl is not the odd one out because it is a state capital, just like Agartala and Shillong. Agartala is also not the odd one out since it is the capital of Tripura and clearly belongs to the same group of capitals. Shillong is not the odd one out because it is the capital city of Meghalaya and fits with the other capitals. Darjeeling differs from these three because it is not a state capital but a famous hill station in West Bengal. Common Pitfalls: Learners sometimes get distracted by the fact that Darjeeling is extremely famous, and might assume it has capital status simply because of its popularity. Another mistake is to focus only on climate or tourism and forget that the question is about administrative importance. To avoid such errors, it helps to remember at least the basic list of Indian state capitals, especially for important states in the northeast region. Final Answer: The place that is not a state capital and is therefore the odd one out is Darjeeling.

Odd Man Out and Series Questions